Since the days of the horseless carriage all vehicular sun visors have suffered from a major and dangerous deficiency. When the rising or setting sun is sufficiently low on the horizon a driver is not protected by the sun visor against sun blinding from direct rays of the sun and/or bright reflections off other vehicles. This causes highway accidents ranging in severity from minor to fatal, and every year many people are injured or killed in such accidents.
Since vehicle manufacturers have failed to provide a better sun visor design, a number of aftermarket accessory firms have promoted add-on devices which claim to remedy the sun glare problem, but which provide little if any practical benefit. These devices employ transparent tinted filter screens which fold or slide down from the bottom edge of the visor. But instead of blocking the sun's rays, they merely attenuate the rays. The rays still strike the driver's eyes, albeit with less intensity, but nevertheless greatly reduce the driver's ability to see. A further disadvantage is that these screens are always so wide that they cover most of a driver's forward vision, thereby undesirably and unsafely dimming his view of the highway ahead.
Recently one automaker has incorporated a horizontally-slidable opaque panel into its visors which offers the benefit of increased glare protection on the sides of a visor. But the problem of preventing the most dangerous and common form of sun blinding--i.e. from rays passing under the visor--has remained unsolved.
It is clear therefore that an important need exists for a fundamentally improved design for sun visors used in land, sea and air vehicles.